Police say an 18-year-old East Wareham man who was arrested on two counts of assault with intent to murder for allegedly stabbing two Bridgewater brothers in Wareham Sunday morning will be charged with murder after one of his victims died Tuesday morning.

Police said 18-year-old Bridgewater resident Brendan J. Mahoney, who graduated from Bridgewater-Raynham Regional High School in 2012, died at approximately 4 a.m. Tuesday at Rhode Island Hospital. The second victim involved in the stabbing incident, 19-year-old Brian P. Mahoney, who graduated from B-R high school in 2011, remains in critical condition.

Police stated in a press release, "An amended charge of murder is expected to be brought forward against Mr. Grassie through the office of Plymouth County District Attorney Timothy Cruz. The arraignment date and time regarding the charge of murder has not yet been scheduled."

Caitlin Russell

Police say an 18-year-old East Wareham man who was arrested on two counts of assault with intent to murder for allegedly stabbing two Bridgewater brothers in Wareham Sunday morning will be charged with murder after one of his victims died Tuesday morning.

Police said 18-year-old Bridgewater resident Brendan J. Mahoney, who graduated from Bridgewater-Raynham Regional High School in 2012, died at approximately 4 a.m. Tuesday at Rhode Island Hospital. The second victim involved in the stabbing incident, 19-year-old Brian P. Mahoney, who graduated from B-R high school in 2011, remains in critical condition.

Police stated in a press release, "An amended charge of murder is expected to be brought forward against Mr. Grassie through the office of Plymouth County District Attorney Timothy Cruz. The arraignment date and time regarding the charge of murder has not yet been scheduled."

Bryan Grassie, 18, of 16 Bartlett Lane, East Wareham, was initially arrested on two counts of assault with intent to murder for allegedly stabbing the two Bridgewater brothers in Wareham Sunday morning. He was ordered held without bail pending an Aug. 6 dangerousness hearing following arraignment Monday in Wareham District Court.

Police said they arrested Grassie, 18, of 16 Bartlett Lane, East Wareham, without incident at the home of a Plymouth relative at 8:55 Sunday morning.

Grassie’s attorney, Eric Goldman, said during the arraignment Grassie acted in self-defense.

According to a witness, Grassie showed up to a graduation party uninvited, acted belligerently, and was, “making insulting comments and attempting to start altercations.”

The witness states that Grassie left after being asked repeatedly to do so, but as he was walking down the street he made comments to the Mahoney brothers that prompted them to confront him, according to the police report.

The witness watched what he initially thought were punches being thrown until he noticed blood on both brothers, and one of them collapsed to the ground. According to the report, “Grassie reportedly stood there for a moment without saying a word, then calmly turned and walked away.”

Police were called to Priscilla Avenue in East Wareham on a report that two people had been stabbed Sunday at 3:32 a.m. Officers arrived at the scene and found the Mahoney brothers with apparent stab wounds lying on the dirt roadway at the intersection of Hardy Road and Priscilla Avenue, according to a press release.

Chief Richard Stanley, and other Wareham officers, along with state police detectives assigned to Plymouth County District Attorney Tim Cruz’s office, arrested Grassie without incident at the home of the relative in Plymouth.